I have the Osprey Radial 26L that I use to commute to work (about 5 miles each way). They really thought it out well for cycling and it's very well made. It's so comfortable, honestly, sometimes I forget I'm wearing it. I think one of the best parts is that it has a "suspension" system that keeps the bag slightly off your back with only a mesh net against your body. I've never sweat on my back once using this pack. I also like that it has what they call a "kickstand" that lets the back stand upright on flat surfaces. Pretty handy. It also has a built-in rain cover.